1. Field of the Invention
This invention relates to a perimeter, and more particularly to a perimeter that enables a field of vision measurement area to be designated from an eye fundus image.
2. Description of the Prior Art
Perimetry has long had a widely-recognized utility with respect to ailments in the eye fundus. Measurement comprises establishing whether or not the patient can perceive a visual sign displayed at a prescribed brightness within a prescribed field of vision (field of vision dome). There is a relationship between the field of vision and ailments in the eye fundus, so when the eye fundus is being examined by measuring the field of vision, the examiner proceeds by viewing a photograph of the patient's eye fundus, designating a measurement area on another screen, and measuring the field of vision accordingly.
A drawback of the conventional method is that since the examiner has to view a photograph of the eye fundus and then use another screen to designate the measurement area of the field of vision, the area designation is imprecise and efficiency is degraded during the designation.
In recent years, when a fundus camera is used to examine the eye fundus, images of the fundus are recorded on film, or the images are obtained using a video imaging means such as a CCD camera, converted into an electronic form and stored on floppy disk or other such external storage means, or is transferred to another computer via a LAN or the like.